The entire gestation period from pregnancy to delivery usually takes 40 weeks, or 280 days. Obstetrics and gynecology talks about the gestational week from the first day of the last menstrual period, not from ovulation as it is usually called. Therefore, when calculating the due date, you must start counting from the first day of your period. The calculation of the due date must be based on the premise that the menstruation is normal. If your period is not normal, for example, 50-60 days, you need to ask your doctor to correct the week of pregnancy according to the ultrasound of early pregnancy. There are three stages of pregnancy: early pregnancy is from the first day of the last menstrual period to 14 weeks of pregnancy, middle pregnancy is from 14-28 weeks and late pregnancy is from 28-40 weeks. If you are pregnant beyond 40 weeks, it is recommended that you come to the hospital promptly and not later than 41 weeks.